Worse than we thought: Antarctic vulnerability to climate change

From the “Antarctic ice is normal now but just you wait” department….

S_daily_extent_hires S_stddev_timeseries

Above:  most recent data from NSIDC.

….and the UNIVERSITY OF EDINBURGH:


Antarctica’s past shows region’s vulnerability to climate change

Fresh understanding of West Antarctica has revealed how the region’s ice sheet could become unstable in a warming world.

Scientists studying the region’s landscape have determined how it reacted to a period of warming after the coldest point of the most recent Ice Age, some 21,000 years ago.

As the Earth warmed, the West Antarctic Ice Sheet reached a tipping point after which it thinned relatively quickly, losing 400m of thickness in 3,000 years, researchers found. This caused sea levels around the world to increase by up to two metres.

Their findings will help scientists understand how the region may behave under future environmental change.

Researchers studied peaks protruding through ice in the Ellsworth Mountains on the Atlantic coast of the continent, to determine how the land’s ice coverage has changed since the Ice Age.

Scientists used chemical technology – known as exposure dating – to calculate how long rocks on the mountainside had been free from ice cover. They used their results to determine how the height of the ice sheet had changed over thousands of years.

They found that this sector of the ice sheet – close to the Weddell Sea – had remained covered with thick ice long after other parts of the Earth had begun to emerge from the Ice Age. Heavier snowfall, caused by warmer air, probably helped to maintain the ice thickness.

As the seas warmed, ice at the coast began to be lost to the oceans. Eventually, a tipping point was reached after which the ice sheet thinned more rapidly, retreating inland.

The study, carried out in collaboration with Northumbria University, Newcastle University and the Scottish Universities Environmental Research Centre, was published in Nature Communications. It was supported by the Natural Environment Research Council.

Dr Andrew Hein of the University of Edinburgh’s School of GeoSciences, who jointly led the study, said: “West Antarctica has undergone complex changes since the last Ice Age, and it quickly became unstable – similar processes may dominate the future of the region in a warmer world.”

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mar
August 22, 2016 12:03 pm

And this is a problem… Why?

Latitude
Reply to  mar
August 22, 2016 3:13 pm

losing 400m of thickness in 3,000 years,…from a friggin ice age
Almost all of that should be gone already

Bob Boder
August 22, 2016 12:04 pm

Who’d thunk it, it got warmer and the ice melted.

Trebla
Reply to  Bob Boder
August 22, 2016 2:03 pm

Sure it melted, but it took 3,000 years. That would geve very litle time to adapt.

MarkW
August 22, 2016 12:07 pm

1) It’s a single point, yet they are claiming to represent all of Antarctica.
2) 2 meters over 3000 years. That’s less than 7 millimeters per year.
3) Is exposure dating actually accurate enough to make these claims?
4) Does the top few feet of glacier erode the rock enough so that this exposure clock actually starts when the glacier uncovers the rock in question?
5) If the seas were warming and the extent of sea ice decreasing, then the humidity available for snow fall would be increasing, have they factored increased snow fall into their “exposure” calculations?

Bob Boder
Reply to  MarkW
August 22, 2016 12:17 pm

“2) 7 millimeters a year”
You don’t think that’s an issue that’s and inch every 3.5 years or so. Heck in thirty years I would have to raise my sea wall more than half a foot just to stay even.
(sarc off now)

Marcus
Reply to  Bob Boder
August 22, 2016 12:41 pm

…Whew…You had me worried there for few seconds… ;o)

Patrick B
Reply to  Bob Boder
August 23, 2016 6:07 am

Don’t forget the “up to” weasel language; that means the rise might have been significantly less. As a chemistry major, I don’t think even once in all my science education did the lab instructions include “up to” (or “may have” or “could” etc.). Science has no use for such vagueness unless it is discussing alternate, unproven theories or results with inherent error margins that prevent definitive statements (and thus prevent proof).

Phil R
Reply to  MarkW
August 22, 2016 12:48 pm

Please check my math, but it’s even worse than they thought. 2 meters (2000 mm)/3000 years is only 0.7 mm/yr.

KRM
Reply to  MarkW
August 22, 2016 3:15 pm

Where did you get 2 m over 3000 yrs. I read 400 m over 3000 yrs, which is 133 mm/yr.

The other Phil
Reply to  KRM
August 22, 2016 3:26 pm

400 meters is the ice thickness in Antarctica. The melt cover the entire ocean contributing 2 meters. Over a period of 3000 years.

Reply to  KRM
August 22, 2016 3:29 pm

As the Earth warmed, the West Antarctic Ice Sheet reached a tipping point after which it thinned relatively quickly, losing 400m of thickness in 3,000 years, researchers found. This caused sea levels around the world to increase by up to two metres.
400m of ice melted. Sea level rose two meters (2,000mm).
Science is hard.

emsnews
Reply to  KRM
August 23, 2016 6:31 am

Reading is hard! 🙂

Phil R
Reply to  KRM
August 23, 2016 6:33 am

KRM,
Sorry, I may not have been clear. I was referring to the 2m sea level rise referenced in the post and to which I think MarkW was referring.

MarkW
August 22, 2016 12:08 pm

6) We know from modern studies that the edges of the Antarctic continent are more impacted by changes in sea temperature than is the interior.

Brad
Reply to  MarkW
August 23, 2016 8:51 am

Did they also conclude water is wet?

Bob Boder
August 22, 2016 12:09 pm

Anybody look at the NSIDC artic map? it looks like some one cut a piece of ice out the same size and shape as Great Britton, wonder what that could mean? Spooky maybe its a sign.

Brian H
Reply to  Bob Boder
August 25, 2016 2:02 am

Arctic

Bruce Cobb
August 22, 2016 12:12 pm

Comparing today’s climate with that at the end of the ice age is sheer idiocy.

August 22, 2016 12:36 pm

Didn’t sea level rise some 500 feet from 22,000 years to 10,000 years ago?

ShrNfr
August 22, 2016 12:54 pm

My word, with the removal of that much ice, the entire continent might tip over. Just think of what would happen to the penguin rookeries! Opus will be the new polar bear.

Brian H
Reply to  ShrNfr
August 25, 2016 2:05 am

It won’t tip, but it will rise.

Kevin Hearle
August 22, 2016 12:59 pm

Hi Mark W, 2M = 2000mm /3000yrs =0.7mm/yr exactly. But given variability in the weather and climate not bang on every year. Cheers from downunder

PA
August 22, 2016 1:12 pm

1. A picture of sea ice extent doesn’t have anything to do with anything.
2. Antarctica isn’t losing ice.
https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses
A new NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers.
The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report, which says that Antarctica is overall losing land ice.
According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed to 82 billion tons of ice per year between 2003 and 2008.

3. Antarctica really isn’t losing land ice:
http://tycho.usno.navy.mil/lod.1973-may2015.jpg
http://spacemath.gsfc.nasa.gov/earth/6Page58.pdf
The length of day should be getting 0.24 milliseconds longer each decade, and that rate should be higher and accelerating if the Antarctic was melting. Clearly that isn’t happening.as illustrated in the above chart.

Reply to  Stephen Rasey
August 22, 2016 1:40 pm

comment image

The other Phil
Reply to  Stephen Rasey
August 22, 2016 3:29 pm

It isn’t the past 3000 years. It was a 3000 year period starting 21,000 years ago.

PA
Reply to  The other Phil
August 22, 2016 6:46 pm

http://www.sott.net/image/s9/188229/full/sea_level_curve_200kyr.jpg
The problem is it is a crock. The sea is getting deeper than it was during previous interglacials and previous interglacials were warmer.
The amount we have pumped groundwater and increased runoff (only 40% of precipitation evaporates) is the amount the sea level might rise.
There are three stages: no ice, about about 16 million km2, and about 50 km2
We are at 16 million km2. There hasn’t been less ice in 3 million years. The sea level might continue to rise 7 inches/century until it gets a meter or two higher. Then again it might not. The sea level was higher 1000 years ago so obviously it was a lot lower between here and there.

tty
Reply to  The other Phil
August 23, 2016 1:34 am

No, it wasn’t in the last 3,000 year, and no it wasn’t 21,000 years ago. It was in the Mid-Holocene between 6,500 and 3500 years ago. That press release is a mess, presumably written by some “climate communicator”. Read the paper:
http://www.nature.com/articles/ncomms12511
Must have been all those sumerian SUV’s

Rob R
August 22, 2016 2:32 pm

Have they considered that the loss of ice in West Antarctica is mainly a consequence of rising sea level rather than a cause of it? If sea level rises due to melting of land-based ice in the Northern Hemisphere (as it did), then the water covering the Antarctic continental shelf gets deeper. This causes a retreat of Antarctic glacier and ice-shelf grounding lines, which destabilises the land-based ice sheet somewhat. So loss of ice mass in Antarctica can, at least partially, be a passive response to Northern Hemisphere ice-loss. Ice loss in Antarctica is not just controlled by the warmth of the climate around the fringes of the continent. Further, the 2 to 3 m rise in sea level referred to in the above article was almost certainly mainly produced as a feedback to events in the Northern Hemisphere. The ultimate cause is probably not to be found either in, or around Antactica.
So the current and future sensitivity of West Antarctica to another episode of massive ice loss is probably tied directly to the stability of the Greenland icesheet.

John Boles
August 22, 2016 2:42 pm

It seems that British and Australians are the most adamant warmists, most alarmist?

Reply to  John Boles
August 22, 2016 2:55 pm

Our Director of Public Prosecutions, equivalent to a DA, hasn’t quite got round to advocating the legal harassment of those who dare to question the consensus – yet.

ozspeaksup
Reply to  John Boles
August 23, 2016 4:44 am

Aus has some well supported by Govvy media like ABC
as example today
they run an item saying the ice shelf Larsen developed a further 22km crack over winter
doom glom tradgedy was hoped for BY the mediashill, the “spurt” t least was honest enough to admit shelf ice doesnt rise sea levels
but
then just had to add the “fear” that once the shelf breaks off it might allow land ice to slip off to sea faster.
nearly smashed the radio!

August 22, 2016 3:51 pm

I find it interesting that any of these types of studies present an ‘elephant in the room’ as they look to the past. We see our little slow warming out of the LIA is nothing compared to all manner of natural variation in the past.
But, with a straight face they use paleo climate to try to increase public concern of man caused warming.
With a straight face and actual science behind them, they should be helping Canadians and Britains to figure out where to move their population when Ice Age conditions inevitably return. That’s a real and looming climate concern yet ‘the science is settled’ crowd still cannot explain the reasons that form the upper and lower bounds the climate has been oscillating between in the recent geologic past.
So predictable…..

August 22, 2016 3:59 pm

“Scientists studying the region’s landscape have determined how it reacted to a period of warming after the coldest point of the most recent Ice Age, some 21,000 years ago.”
earliest attempts at a bronze age?

August 22, 2016 4:07 pm

Alternate headline:
“Antarctic ice levels 2 weeks ahead of most recent decade’s norm”

August 22, 2016 4:33 pm

“As the Earth warmed, the West Antarctic Ice Sheet reached a tipping point after which it thinned relatively quickly, losing 400m of thickness in 3,000 years, researchers found. This caused sea levels around the world to increase by up to two metres…”

21,000 years ago, the Earth warmed up enough that West Antarctica lost 400 meters, (437 yards) of ice thickness; causing the sea level to rise 2 meters?
So much for this year being the ‘hottest ever!’
And West Antarctica lost 400m of ice… From on top where the warm air collects?
Was West Antarctica so removed or isolated from Antarctica that West Antarctica wilted while Antarctica froze?
Just how warm, (hot?), did West Antarctica allegedly become?

“…Researchers studied peaks protruding through ice in the Ellsworth Mountains on the Atlantic coast of the continent, to determine how the land’s ice coverage has changed since the Ice Age.
Scientists used chemical technology – known as exposure dating – to calculate how long rocks on the mountainside had been free from ice cover. They used their results to determine how the height of the ice sheet had changed over thousands of years.
They found that this sector of the ice sheet – close to the Weddell Sea – had remained covered with thick ice long after other parts of the Earth had begun to emerge from the Ice Age. Heavier snowfall, caused by warmer air, probably helped to maintain the ice thickness…”

Now, West Antarctica has peaks that remained covered by ice, “long after other parts of the Earth had begun to emerge from the Ice Age”.
Which is it!?
Two meters of sea level increase due to 400m of ice melt or less ice melt?
Heavier snowfall? Backed up by ice core analysis? Or solely guessed by rock exposure?
What happens when a rock is covered/uncovered repeatedly over millennia?

“…As the seas warmed, ice at the coast began to be lost to the oceans. Eventually, a tipping point was reached after which the ice sheet thinned more rapidly, retreating inland…”

Horrors! The dreaded tipping point!
Which means exactly what? As in exactly what happened that makes it a tipping point?
“As the seas warmed…”
Nice generic statement. Without substance or meaning.
“The ice sheet thinned rapidly…”
Given that Antarctica is frequently/annually surrounded by sea ice, just what does this vague bit of wordplay actually mean?
Summation:
Another bafflegab piece throwing around loose pieces of research interspersed with long leaps in logic and incredible assumptions.
What I find myself wondering, is if all of this ice melted from the tops of Antarctica, just what does losing so much Holocene ice do to ice core reconstructions.

tty
Reply to  ATheoK
August 23, 2016 1:57 am

“Given that Antarctica is frequently/annually surrounded by sea ice, just what does this vague bit of wordplay actually mean?”
In this case about 130 millimeter (five inches) of thinning per year, which is rapid for a glacier, and equal to a sea-level rise of about 0.5-0.7 millimeters per year. However most of the rise was probably near the beginning and the end of the period. The sea-ice around Antarctica is completely irrelevant.

Reply to  ATheoK
August 23, 2016 8:59 am

tty is back again, lost, wandering making pointless and often highly erroneous comments.
Hey tty, maybe you should read the whole article above!
It is not a discussion about today’s ice, or the alarmist fabrications regarding virtually non-existent melting.
The discussion covers 21,000 years of Antarctic ice. Along with chemical surface testing of exposed rocks that reveal all.
Though, I suppose it would be too much to hope you actually learn something from reading the article.

tty
Reply to  ATheoK
August 23, 2016 9:34 am

ATheoK
I did read the paper. You clearly didn’t. Yes, it is concerned with the interval since the LGM, but the main lowering of the glacier level happened 6,500-3,500 BP.
By the way exposure dating is based on radionuclides, not chemistry.

Reply to  ATheoK
August 23, 2016 10:34 am

Oh Dear!
tty completely forgot that he started this comment series with his fallacious claim about current Antarctic ice loss.
The old strawman argument; when a response is tendered, tty argues a completely different point.
So sad tty, so dismal, so shallow.

“…Whole rock samples were crushed and sieved to obtain the 250–710 μm fraction. Be and Al were selectively extracted from the quartz component of the whole-rock sample…”

Apparently, tty never took chemistry either.
I wonder just how all of those radio-nuclides were extracted and concentrated without chemistry…
Typical CAGW alarmist type education tty, zero understanding of science, especially the physical sciences; e.g. geology, chemistry, physics.

“…In this study, we favour the youngest exposure age at each altitude to best represent the elevation of the ice surface at the time…”

“…We sampled the freshest-appearing, quartz-bearing, brick-sized clasts resting on flat bedrock to minimize problems of post-depositional movement and self-shielding…”

“When considering all sites together, the modelling suggests a lower and linear thinning rate of 8.8±0.2 cm a−1, but initiated a little earlier at about 8.5–9 ka. The exercise demonstrates that our conclusion of a mid-Holocene pulse of thinning, which was complete by 3.5 ka, is not sensitive to our interpretation based on the youngest exposure. In Supplementary Fig. 4, we increase the range to include all 10Be exposure ages <15 ka, and then with three clear outliers (3σ) removed to obtain a linear regression through all deglacial exposure ages. The model suggests the onset of initial deglaciation was at 9–10.5 ka, with a lower average thinning rate of 8.1±0.2 cm a−1."

The research comes off far worse in the full paper.
&bull Now it is obvious that they cherry picked samples.
&bull Made giant leaps in assumptions, without evidence. What evidence they do have, they collected or generated after settling on their findings first.
&bull Used models to flesh out and bless their whole preconceived morass of assumptions.

“…Blue-ice moraines form on the windswept ice surface at the foot of the mountains and remnants of earlier blue-ice moraines occur up to 650 m above the present ice surface. Little-weathered blue-ice deposits extend up to 475 m above the ice surface and mark the decline in ice surface elevation since the LGM…”

Don’t you like that beginning assumption?
Ice stuck to the side of mountains is proof of previous maximum height ice sheets? Quite a leap there.
“On top of old Smokey,
All covered with snow,
I lost my true lover,
For courting too slow”

tty
Reply to  ATheoK
August 23, 2016 1:17 pm

ATheoK
I have never made any claim whatsoever about current ice-loss, if any. My figures was for the main thinning period 6.5-3.5 KA BP. Perhaps I should have stated this explicitly, but since this whole thread is about this thinning episode it seemed rather unnecessary. But not when trying to explain something to you apparently.
“I wonder just how all of those radio-nuclides were extracted and concentrated without chemistry…”
It is done by accelerator mass spectrometry (AMS), but you are welcome to try to isolate and measure 10Be by chemical methods. Good Luck!
“Typical CAGW alarmist type education tty, zero understanding of science, especially the physical sciences; e.g. geology, chemistry, physics.”
Amusingly enough I majored in physics.
“Ice stuck to the side of mountains is proof of previous maximum height ice sheets?”
Moraine consists of ROCKS not ice. And yes, the altitude of lateral moraines/trimlines do indicate the maximum vertical extent of glaciation. You seem to be rather remarkably ignorant about geology by the way.

Reply to  ATheoK
August 23, 2016 8:18 pm

So sad tty, you’re still confused.

“…It is done by accelerator mass spectrometry (AMS), but you are welcome to try to isolate and measure 10Be by chemical methods. Good Luck!…”

And we suppose all of those beryllium atoms just happened to be in a nice concentrated solution for testing in the mass spectrometer?
Just picked up on those loose quartzite surface rocks?

“…Moraine consists of ROCKS not ice…”

Really? And just how do those silly twits posing as Antarctic researchers just happen to know they are “blue ice moraines”?
Remember?

“…Blue-ice moraines form on the windswept ice surface at the foot of the mountains and remnants of earlier blue-ice moraines occur up to 650 m above the present ice surface. Little-weathered blue-ice deposits extend up to 475 m above the ice surface and mark the decline in ice surface elevation since the LGM…”

“Itty bitty little blue ice deposits.”
“Remnants of earlier blue-ice moraines”
Definition of moraine
1: an accumulation of earth and stones carried and finally deposited by a glacier”
To have a moraine, requires accumulated snow, forming into moving ice or glacier.
Melting or sublimation of the ice causes material picked up by the glacier to fall; especially at glacier terminations.
A moraine is chiefly dirt, rocks, soil and debris. The debris often includes ice if the weather is cold enough.
Oddly, Antarctic weather is generally more than cold enough.
From itty bitty blue ice deposits and remnants of earlier blue ice moraines, the researchers immediately jump to Antarctic ice levels 400m higher.
Amazingly, moraines, lateral or not, indicate moving ice, i.e. glaciers, not previous heights of total ice flowing away from the mountains.
All that is required is sufficient accumulation of snow to form a glacier. When enough snow accumulates, ice forms and eventually the ice begins to flow, grating up debris.
Discovery of evidence for glaciers does not equate to assumptions for 400m of ice.
Ice covered rocks are not evidence of 400m of ice. Instead they are evidence that for significant periods of time, ice covered them…

tty states: “You seem to be rather remarkably ignorant about geology by the way.”

And you assume to lecture others about geology?
Suuure tty…
Excuse me, while I guffaw loudly.

Alan Ranger
August 22, 2016 5:35 pm

Always interesting that WEST Antarctic goes under the microscope. The obvious question to ask is why the sea surface temperatures are anomalously high around that peninsula poking out into the sea. And why is that (non-representative) peninsula there in the first place? The obvious answer is that it was formed by a chain of volcanoes, with many new young active ones being recently discovered beneath the waves.
http://www.coolantarctica.com/Antarctica%20fact%20file/science/Antarctica-warming-2004.jpg
Might explain a few things.

Reply to  Alan Ranger
August 23, 2016 9:53 am

It is just a little more than that Alan.
Those volcanoes are the southernmost terminus of the ‘Ring of Fire’ where geological forces are in active motion.comment image?dl=0
Antarctica plate
“…However, the Pacific-Antarctic Ridge is a location where the two plates (Pacific and Antarctic) are moving in the same general direction. The ridge forms due to the Pacific Plate motion that is around four times faster than the Antarctic plate. Relative to each other, these plates also diverge forming the ridge.”
With some discussion regarding whether the magma chamber below West Antarctica is evidence of a mantle plume, or not.
http://www.mantleplumes.org/images/AntarcticaFig1_800.jpg

Justthinkin
August 22, 2016 7:28 pm

“similar processes may dominate the future of the region in a warmer world.”
There’s that lovely qualifier again; MAY. Yeah. I may win the lottery tomorrow and all the climate scammers may be thrown in jail. When did “science” start using such weasel words?

Justthinkin
August 22, 2016 7:31 pm

“similar processes may dominate the future of the region in a warmer world.”
There’s that weasel word again; MAY. Yeah. I MAY win the lottery tomorrow and all the climate scammers MAY get thrown in jail. When did “science” start using such weasel words?

August 22, 2016 8:14 pm

““West Antarctica has undergone complex changes since the last Ice Age, and it quickly became unstable – similar processes may dominate the future of the region in a warmer world.”
If this is about the Antarctic Peninsula, the one that extends almost to South America, why would the region not be vulnerable during an interglacial?
After all, the Peninsula is as close to the Equator as Iceland.and the Bering Strait Alaska.
This part of Alaska is not covered by a glacier.
https://www.google.com/maps/@65.6428079,-167.620477,40962m/data=!3m1!1e3

tty
Reply to  Frederick Colbourne
August 23, 2016 1:59 am

Not the Peninsula – Ellsworth mountain area. Forget about that press-release, it’s largely crap. Read the paper:
http://www.nature.com/articles/ncomms12511

Johann Wundersamer
August 22, 2016 10:16 pm

From the “Antarctic ice is normal now but just you wait” department….
– highly addictive potentials !

Johann Wundersamer
August 23, 2016 12:17 am

“West Antarctica has undergone complex changes since the last Ice Age, and it quickly became unstable – similar processes may dominate the future of the region in a warmer world.”
______________________________________
Said “future” is the remaining time of “our” interglacial. Only fact we know for sure.

4TimesAYear
August 23, 2016 1:01 am

Maybe the question they should be asking is what caused it to accumulate all that ice and snow after being a veritable paradise before: http://www.nap.edu/read/12168/chapter/4#22

Johann Wundersamer
Reply to  4TimesAYear
August 24, 2016 2:31 am

Wow. Always astounded how much more there is to know.

tty
August 23, 2016 1:49 am

It is interesting to note that the same research group published another paper, also in Nature Communications, about their research in the Ellsworth Range a few months ago. Somehow it didn’t make it into the MSM. The title tells the story why:
“Evidence for the stability of the West Antarctic Ice Sheet divide for 1.4 million years”
http://www.nature.com/articles/ncomms10325
This latest paper is
“Mid-Holocene pulse of thinning in the Weddell Sea sector of the West Antarctic ice sheet”
http://www.nature.com/articles/ncomms12511
I recommend that you read it (it isn’t very difficult), since the press release seems to have been written to be intentionally misleading (as press releases quite often are). For example it is quite impossible to guess from the press-release when this thinning happened (6,500-3,500 years ago).
I have been following this group, and in my opinion they are producing good science and their papers only contain the minimum obeisances to CAGW required for publication.

RoHa
August 23, 2016 4:41 am

Just clarify, are we talking about cold ice, which results from Ice Ages and the like, or warm ice, which (like warm snow) results from Man Made Global Warming?

RAH
August 23, 2016 6:14 am

I don’t think it is possible for us to go for six months without some article about some ice shelf melting or threatening to break away in the Antarctic getting into the regular media. It all gets to be very redundant and hard for even those of us interested to not begin to see it as more blah blah blah. If something really big having global implications did happen it would be hard for them to get the attention of the layman because of their constant cries of wolf over the last decades. The average person would see the news and think ‘Same S%!t different day. So what’s new?’ And to be quite frank that is exactly my reaction to this article.

Craig Loehle
August 23, 2016 6:33 am

The “rapid” melting back then caused 2m sea level rise in 3,000 years. Yikes! so fast! we are going to drown! Oh….3,000 years…never mind…

Geoff Sherrington
August 23, 2016 6:36 am

Has there ever been a paper showing an unconformity in Antarctic ice layers shown in drill cores? If ice is lost from the land based portion, an unconformity is a plausible first signal. BTW it would play hell with chronologies.
If no unconformity has been found, there is no point in hypotheses about ice loss from melting.
Geoff

tty
Reply to  Geoff Sherrington
August 23, 2016 9:46 am

Ice doesn’t melt in Antarctica. It calves into the sea or sublimates.
In Greenland “unconformities” (melt layers) occasionally occur, especially in the south. In Antarctica they are absent or extremely rare.They certainly never occur up near the ice-divides where ice-cores are drilled.
The lowered level of the glacier in this case was entirely due to increased calving (marine draw-down).
Ice in Antarctica does sublimate, i e turn directly from ice to water vapor. This paper is based on dating “blue-ice moraines” left by such sublimation.

tty
Reply to  Geoff Sherrington
August 23, 2016 9:49 am

PS
Perhaps I should have mentioned that melting does occur in some areas at the bottom of the ice-sheet by geothermal heat. That is the reason that there are lakes under the ice in some areas.

Geoff Sherrington
Reply to  tty
August 23, 2016 4:41 pm

TTY,
Thank you. All that you commented has been known for a long time.
This is what I am getting at. If Antarctic ice is going to contribute to ocean level rise where does the added water come from?
For ice above land, sublimation is one way. Has it been measured accurately? Another way is basal meltwater, but it is hardly related to CO2. Another path is the toothpaste method, squeezing ice into the sea, but it’s importance is limited to the relatively small area of glaciers.
Of course, melting of ice now floating on water does not much affect levels, Avogadro.
When there are several theoretical ways for ocean levels to be affected, often one or two might dominate. Which are the major postulated players and how well are they quantified?
Yes, I am aware of glaciers on bedrock in shallow water and some of their complications.
Geoff

Johann Wundersamer
Reply to  tty
August 24, 2016 2:38 am

Geoff Sherrington on August 23, 2016 at 4:41 pm
TTY,
Thank you. All that you commented has been known for a long time.
_______________________________________
Yep, but – wrong adress. Please tell that Obama, Merkel and IPCC.
They should know too.

August 23, 2016 11:17 am

BS!

August 23, 2016 4:30 pm

Chicken Little is alive and well.

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